الفهرس | Only 14 pages are availabe for public view |
Abstract The present investigation was divided into two parts, the first part represented in collection of naturally infected cases with mycotic infection and was performed. on ten chickens farms of about 1000-5000 birds capacity balady chickens of various age 1-4 month at Kaluobia governorate. The samples were collected from November 1999 to May 2001. The collected samples were subjected for mycological and pathological examinations. The second part represented in experimental infection by using stains of Aspergillus frimigatus and Aspergillus flavus isolated from natural infected cases. The mycological examination of the naturally infected cases revealed the presence of Aspergillus flimigatus strain in the lungs, liver and kidneys of the examined cases. Moreovere, Aspergillus flimigatus was isolated from the eye only of some naturally infected~ examined cases. While Aspergillus fle was isolated from the lungs and liver of naturally infected examined cases. In naturally infected cases, the clinical signs included depression, emaciation diaffhoea, severe thirst, dysponea and coughing. Grossly mycotic nodules of about 2-5 mm in diameter were observed in the lungs and liver. These nodules were also detected in the kidneys and the eye in cases of Aspergillus fuimigatus infection. Greenish patches of the mold were detected in the lungs of some examined cases. The most prominent microscopic lesions represented by presence of typical mycotic nodules in the lungs, liver, kidneys and eye. These nodules consisted of central caseous necrosis surrounded with a zone of granulation tissue with the presence of flingal hyphae and spores in the caseated mass. Moreover, perivascular leukocytic cellular aggregation was detected in the lungs and liver. While the experimental infections caused by gjllus flimigatus and Aspergillus flavus were performed via two routes of infection. The :irst one was intra-cardiac route in which we inject two groups, the first group consisted of thirty chicks at 14-days old age injected with 0.5 X io~ spores of Aspergillus fumigatus in the heart and the second group consisted of another thirty chicks injected at 14-days old age with 0.5 X 1 o~ spores of Aspergillus flavus. While the second route was intra-nasal instillation in which we infect two groups, the first group in which we instillated 0.5 X i0~ spores of Aspergillus flimigatus in the nose of thirty chicks. While the second group in which we instillated 0.5 X io~ spores of Aspergillus flavus in the nose of another thirty chicks. The intra-cardiac injection of 14-days old age chicks with Aspergillus fiamigatus and Aspergillus flavus spores, resulted in development of characteristic gross and microscopic lesions of aspergillosis. Clinically the infected chickens showed depression, emaciation, dysponea, torticollis and incoordination. Few chickens showed diarrhoea. Grossly, multiple mycotic nodules, that increased in size by time and usually reach about 1-5 mm in diameter were found in lungs, heart, liver, brain and the muscles. Also these nodules were found in the intestine, spleen and kidneys in few numbers of infected chickens. Moreover the lungs appeared covered with. a green layer of the fungus. The most prominant microscopic lesions represented mainly by congestion of the blood vessels, with development of multiple mycotic granulomas in the lungs, liver, heart, brain and the skeletal muscles. These granulomas consisted of caseated mass surrounded with a wide zone of granulation tissue and giant cells with the presence of ffingal hyphae and spores. Intra-nasal instillation of 2-days-old age chicks with Aspergillus fumigatus and Aspergillus flavus spores, resulted in development of characteristic gross and microscopic lesions mainly in the respiraatory system, besides the liver and heart of some infected cases. Clinically, the infected chicks showed depression, emaciation, dyspnea and coughing. Grossly, mycotic nodules in the lungs of various size about 1-3 mm in diameter were detected. The lungs of some chickens infected with Aspergillus fhmigatus appeared covered with a green layer of the fungus. While numerous mycotic granulomas in the lungs were detected. Some of these mycotic granulomas found in the liver of some chickens. Microscopically, these gran.ulomas consisted of central caseous necrosis surrounded with a zone of granulation tissue with the presence of fungal hyphae and spores. AsperRillus fumigatus is more pathogenic than Aspergillus fivus. Intra-cardiac route cf infection produced generalized lesions while Intra nasal route of infection produced lesions mainly in the respiratory system. |